Maybe in some areas but here in Yorkshire the likes of Sheffield, Doncaster and York seem to manage perfectly well without ticket barriers.
And when you have to endure the ridiculous queues to get through the barriers at Leeds at peak times, you can understand why many feel ticket barriers are a massive inconvenience to solve a relatively minor problem - ie fare dodging.
I wouldn't say it's a minor problem - on some parts of the railway it's rife.
If you don't get on top of it, more will do it, then those who do pay will (quite reasonably) decide "why should I keep subsidising this?".
I can see both sides of the argument. Gates can be a nuisance, especially if you're last in the queue off a busy train, or have luggage, an unusual ticket etc. But there's no doubt they do bring in revenue, especially for journeys in/out of major towns and cities, and they also have some benefit in keeping undesirables out of the railway. They also make life easier for train crews as they reduce the numbers on the train without tickets.
On balance I can tolerate them, but they need to be well laid out, and supported by other forms of inspection. Also TOCs need to ensure stations have adequate means buy tickets, and this includes small stations. The queues found at Manchester Piccadilly or the awkward Finsbury Park layout is not how it should be done.